341 research outputs found

    Estudo da vegetação arbórea e arbustiva adequada a projetos de engenharia natural em Portugal

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    Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia - ULA Engenharia Natural (EN) usa as raízes das plantas no reforço e proteção dos solos, aproveitando os seus recursos endógenos, utilizando uma energia renovável e promovendo a aceleração da sucessão ecológica. Esta técnica, apesar de pouco divulgada em Portugal, demonstra ser uma boa alternativa ao uso do betão na retenção de solo em taludes e encostas, áreas que se caraterizam pela existência de fatores edáficos e de humidade limitantes. Foram estudadas árvores e arbustos da flora de Portugal continental no sentido de se obter um conjunto de espécies, ainda não utilizadas em projetos de EN, com suposta capacidade de propagação vegetativa. Foram selecionadas como espécies candidatas a submeterem-se a ensaios, aquelas que apresentaram ampla distribuição geográfica, demonstrando, aparentemente, maior utilidade em todo o território de Portugal continental. Os resultados quantitativos do enraizamento adventício e das características biotécnicas dos sistemas radiculares das quatro espécies testadas, Fraxinus angustifolia Vahl, Sambucus nigra L., Rosmarinus officinalis L., Viburnum tinus L., permitem confirmar que todas as quatro espécies se adaptam aos projetos de EN, e ainda, que existe uma relação positiva entre o desenvolvimento da parte aérea e da parte hipogeia das plantas, com particular destaque para as novas raíze

    Selection of suitable species for bioengineering

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    Soil bioengineering was developed in central Europe after World War II and in Mediterranean Europe in the last twenty years; soil bioengineering has been recently applied also in Portugal suggesting its potential future development. Soil bioengineering, to consolidate and stabilize sliding down slopes, uses indigenous trees and shrubs with good vegetative propagation. A key feature of these species, employed as cuttings or as whole plants, is to not get damaged when their stems are buried in the ground about one meter. In this article is selected, from Mainland Portugal flora, a list of plant species, starting from scientific literature of Portugal, Central Europe and Central and Southern Europe, and using practical knowledge developed in Southern Italy. Afterwards groups of species are defined as (i) appropriate for soil bioengineering works to do in Portugal and (ii) probably adequate, requiring further researches to improve the knowledge about their feature. Tests are planned to assess the biotechnical features of this second group

    Glucose regulates insulin mitogenic effect by modulating SHP-2 activation and localization in JAr cells.

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    The glucose effect on cell growth has been investigated in the JAr human choriocarcinoma cells. When JAr cells were cultured in the presence of 6 mm glucose (LG), proliferation and thymidine incorporation were induced by serum, epidermal growth factor, and insulin-like growth factor 1 but not by insulin. In contrast, at 25 mm glucose (HG), proliferation and thymidine incorporation were stimulated by insulin, serum, epidermal growth factor, and insulin-like growth factor 1 to a comparable extent, whereas basal levels were 25% lower than those in LG. HG culturing also enhanced insulin-stimulated insulin receptor and insulin receptor substrate 1 (IRS1) tyrosine phosphorylations while decreasing basal phosphorylations. These actions of glucose were accompanied by an increase in cellular tyrosine phosphatase activity. The activity of SHP-2 in HG-treated JAr cells was 400% of that measured in LG-treated cells. SHP-2 co-precipitation with IRS1 was also increased in HG-treated cells. SHP-2 was mainly cytosolic in LG-treated cells. However, HG culturing largely redistributed SHP-2 to the internal membrane compartment, where tyrosine-phosphorylated IRS1 predominantly localizes. Further exposure to insulin rescued SHP-2 cytosolic localization, thereby preventing its interaction with IRS1. Antisense inhibition of SHP-2 reverted the effect of HG on basal and insulin-stimulated insulin receptor and IRS1 phosphorylation as well as that on thymidine incorporation. Thus, in JAr cells, glucose modulates insulin mitogenic action by modulating SHP-2 activity and intracellular localization

    Minimally Invasive Trans-Axillary versus Full Sternotomy Mitral Valve Repair: A Propensity Score-Matched Analysis on Mid-Term Outcomes

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    Background and Objectives: Minimally invasive cardiac surgery is an established approach for the treatment of heart valve pathologies and is associated with excellent technical and early postoperative outcomes. Data from medium- and long-term longitudinal evaluation of patients who underwent mitral valve repair (MVr) through transaxillary approach (TAxA) are still lacking. The aim of this study is to investigate mid-term results in patients who underwent TAxA MVr. Materials and Methods: Prospectively collected data of patients who underwent first-time MVr for MV regurgitation between 2017 and 2022, were reviewed. A total of 308 patients received TAxA, while in 220 cases, traditional full sternotomy (FS) was performed. Concomitant aortic and coronary artery bypass grafting (CABG) procedures, infective endocarditis or urgent operations were excluded. A propensity match (PS) analysis was used to overcome preoperative differences between the populations. Follow-up data were retrieved from outpatients' clinic, telephone calls and municipal administration records. Results: After PS-matching, two well-balanced cohorts of 171 patients were analysed. The overall 30-day mortality rate was 0.6% in both cohorts. No statistical difference in postoperative complications was reported. TAxA cohort experienced earlier postoperative extubation (p < 0.001) with a higher rate of extubation performed in the operating theatre (p < 0.001), shorter intensive care unit (ICU) stay (p < 0.001), and reduced hospitalization with 51% of patients discharged home (p < 0.001). Estimated survival at 5 years was 98.8% in TAxA vs. 93.6% in FS cohort (Log rank p = 0.15). The cumulative incidence of reoperation was 2.6% and 4.4% at 5 years, respectively, in TAxA and FS cohorts (Gray test p = 0.49). Conclusions: TAxA approach for MVr was associated with low rates of in-hospital mortality and major postoperative complications being furthermore associated with shorter mechanical ventilation time, shorter ICU stay and reduced hospitalization with a higher rate of patients able to be discharged home. At mid-term, TAxA was associated with excellent survival and low rate of MV reoperatio

    How SARS-CoV-2 Infection Impacts the Management of Patients with Vulvar Cancer: Experience in a Third-Level Hospital of Southern Italy

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    : Background: Since February 2020, the spread of Coronavirus Disease 2019 (COVID-19) in Italy has induced the government to call for lockdown of any activity apart from primary needs, and changing the lives of each of us. All that has dramatically impacted the management of patients affected by cancer. Patients with vulvar cancer (VC) represent a particularly frail population because they are elderly and affected by multiple comorbidities. The aim of this study is to evaluate the clinical impact of the SARS-CoV-2 infection on VC patients in terms of delay or impossibility of carrying out the scheduled treatment. Methods: The medical records of patients affected by vulvar tumors, referred to "DAI Materno-Infantile" of AOU Federico II of Naples between February 2020 and January 2022 were retrospectively analyzed. The presence of a positive reverse transcription-polymerase chain reaction (RT-PCR) in nasopharyngeal swab defined the positivity to SARS-CoV-2. Results: Twenty-four patients with VC were analyzed and scheduled for treatment. The median age was 70.7 years (range: 59-80). Seven (29.2%) patients were diagnosed with SARS-CoV-2 infection: In three (42.8%) patients, the treatment was delayed with no apparent consequences, in four (57.2%), the treatment was delayed or changed due to cancer progression and, of these four, one died due to respiratory complications of COVID-19, and one died due to oncologic disease progression. Conclusion: COVID-19 caused, in most cases, significant delays in oncologic treatments and high mortality in our series of patients affected by VC

    Scaling Clinical Trial Matching Using Large Language Models: A Case Study in Oncology

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    Clinical trial matching is a key process in health delivery and discovery. In practice, it is plagued by overwhelming unstructured data and unscalable manual processing. In this paper, we conduct a systematic study on scaling clinical trial matching using large language models (LLMs), with oncology as the focus area. Our study is grounded in a clinical trial matching system currently in test deployment at a large U.S. health network. Initial findings are promising: out of box, cutting-edge LLMs, such as GPT-4, can already structure elaborate eligibility criteria of clinical trials and extract complex matching logic (e.g., nested AND/OR/NOT). While still far from perfect, LLMs substantially outperform prior strong baselines and may serve as a preliminary solution to help triage patient-trial candidates with humans in the loop. Our study also reveals a few significant growth areas for applying LLMs to end-to-end clinical trial matching, such as context limitation and accuracy, especially in structuring patient information from longitudinal medical records.Comment: 24 pages, 5 figures, accepted at Machine Learning for Healthcare (MLHC) 202

    Portal Cavernoma during Pregnancy

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    Portal vein thrombosis (PVT) is characterized by the obstruction of the portal venous system. The venous obstruction can be partial or complete and it is caused by thrombogenic conditions (acquired or hereditary) or nonthrombotic factors. The acquired conditions include abdominal inflammation, infections, surgery, myeloproliferative disorders, obesity, oral contraceptive intake, pregnancy, and postpartum period. Occasionally, it is not possible to recognize any overt cause of PVT. During pregnancy there is an increased venous thromboembolism risk mainly in the systemic venous system and the PVT can occur, but there are no data about its exact prevalence, etiology, and outcome. The portal cavernoma is the cavernomatous transformation of the portal vein. It is a consequence of chronic PVT and occurs when myriads of collateral channels develop to bypass the occlusion. The clinical presentation includes hematemesis due to variceal bleeding, ascites or anaemia, and splenomegaly. The cavernous transformation of the portal vein is easily diagnosed by sonography. We report our case of a 32-year-old, gravida 3 para 2, pregnant woman admitted to our hospital at 13 weeks and 1 day of gestation, clinically asymptomatic. Laboratory test, ultrasound, and endoscopic evaluation were negative. After a detailed counseling, the patient decided on termination of pregnancy at 15 weeks and 1 day of gestation

    Applying Large Language Models for Causal Structure Learning in Non Small Cell Lung Cancer

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    Causal discovery is becoming a key part in medical AI research. These methods can enhance healthcare by identifying causal links between biomarkers, demographics, treatments and outcomes. They can aid medical professionals in choosing more impactful treatments and strategies. In parallel, Large Language Models (LLMs) have shown great potential in identifying patterns and generating insights from text data. In this paper we investigate applying LLMs to the problem of determining the directionality of edges in causal discovery. Specifically, we test our approach on a deidentified set of Non Small Cell Lung Cancer(NSCLC) patients that have both electronic health record and genomic panel data. Graphs are validated using Bayesian Dirichlet estimators using tabular data. Our result shows that LLMs can accurately predict the directionality of edges in causal graphs, outperforming existing state-of-the-art methods. These findings suggests that LLMs can play a significant role in advancing causal discovery and help us better understand complex systems
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